Wire structure and method for designing the same

ABSTRACT

A wire structure defined between a first plane and a second plane is provided. The first plane and the second plane are parallel to each other. The wire structure includes a main body and at least three convex portions. The main body has a center defined by its centroid and a periphery defined by the perimeter of the main body. The convex portions protrude from and are adjacently arranged around the periphery. At least one convex portion is tangent to the first plane, and at least two convex portions are tangent to the second plane. The number of the at least one convex portion tangent to the first plane is not equal to the number of the at least two convex portions tangent to the second plane.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of Ser. No. 13/494,780filed on Jun. 12, 2012, now pending, and entitled “WIRE STRUCTURE ANDMETHOD FOR DESIGNING THE SAME”, the entire disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a wire structure. More particularly,the present invention relates to a wire structure and a design methodthereof, wherein enhanced heat dissipation is achieved in the micronscale by an irregular shape design and by changing the surface area asappropriate.

2. Description of Related Art

The continuous improvement of technology has given rise to a plethora ofelectric appliances and electronic products. An electronic producttypically requires a plurality of wires for transmitting signals andthereby achieving the intended hardware and software objectives.

Conventionally, a wire structure depends on an external heat exchangestructure, such as a fan or fins, to dissipate heat, and the purpose ofproviding the additional heat exchange structure is to increase theefficiency of heat transfer.

However, when wire structures are downsized to the micron scale (about0.010 to 0.999 mm), the issue of heat dissipation differs substantiallyfrom that of the traditional wires, which are in the millimeter scale(about 1 to 2 mm). This difference can be accounted for by the fact thatheat transfer in different scales features different heat dissipationeffects. Besides, the additional heat dissipation structures incur extracosts and occupy considerable space, which is highly undesirable.

U.S. Pat. No. 7,479,597 directs itself to reduce attenuation of highfrequency signal transmissions due to the skin effect which was filed onNov. 28, 2007. The '597 patent discloses a wire structure whose crosssection is defined by a closed curve composed of three to eight convexportions and an equal number of concave portions. The radii of curvatureof the convex portions and of the concave portions are less than onesixth of the overall radius of the closed curve. The radius of the crosssection of the wire ranges from 2 mm to 10 mm and the simple closedcurve has no point where the radius of curvature is less than 0.5 mm.Moreover, the radii of curvature of the convex portions and of theconcave portions can be less than 0.1 mm.

It is well known that the heat dissipation effect of a wire varies withthe surface area of the wire structure. If the dimensions of the wirestructure of the '597 patent are markedly reduced (e.g., to one tenth,one hundredth, or even one thousandth), the perimeter of the closedcurve will become so small that an increase in the surface area of thewire structure is unattainable by the design of the convex portions andthe concave portions, and poor heat dissipation follows. If, however, anadditional heat exchanger is used for more efficient heat dissipation,the convenience of use of the electric appliance in which the wirestructure, and hence the heat exchanger, are provided will becompromised. Therefore, it is a pressing issue to improve heat transferof relatively small wire structures.

Furthermore, in order to form the convex portion and the convex portionon the wire structure. The radius of the cross section of the wireranges should be greater than 2 mm. Thus, the size of the wire structureis greater.

U.S. Pat. No. 6,967,289 directs itself to an electric wire, which isenhanced on transmissibility of high-frequency current, especially toenlarge conductor skin effect in high-frequency current flow. The '289patent discloses a conductive portion formed on cross section thereofinto round shape having a diameter of 0.1-1 mm. The conductive portionis provided with a convexo-concave surface to provide the predeterminedamount of grooves. The electric wire provided with a conductive portionwhich groove has a cross section being formed into any of V-shape,U-shape or trapezoid.

However, due to the diameter of the conductive portion is 0.1-1 mm.Thus, the groove should be a cross section being formed into V-shape,U-shape or trapezoid. Therefore, because of the diameter of theconductive portion is small, the shape of the groove is restricted bythe processing tools and also difficult to manufacturing. In addition,in order to provide the size of wire from 0.1-1 mm, the grooves shouldbe recessed in the wire, and should be manufactured by the cuttingprocess.

Therefore, as described above, the wire structure disclosed in the '597patent merely describe that formed the convex portion and the convexportion on the wire which diameter is greater than 2 mm. The wirestructure of disclosed in the'289 patent merely discloses that if thediameter of the conductive portion is 0.1-1 mm, the groove should bemanufactured by the cutting process. Furthermore, FIG. 3 of the '597patent disclosed a wire structure similar to the wire disclosed in the'289 patent. However, due to the structure of the wire is different withthe '597 patent, the person skill in the art could not recognize anyteaching, suggestion, or motivation to accomplish the cable disclosed inthe '597 patent.

US Patent Publication No. 2009/0025960 directs itself to a cable-typecomposite printed wiring board including a cable component having acoupler abutting a wiring pattern on the wiring board. The '289 patentdiscloses a conductor wire coupler and a shielding wire coupler areconnected to the cable of the cable component. However, the conductorwire coupler and the shielding wire coupler are planetary gear-shaped.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a method for designing a wirestructure, wherein the method includes the steps of: setting N radiallines, setting a circular design line, and designing N identical convexportions. As a wire structure thus designed can dissipate heatefficiently despite its relatively small size, the cost and spaceotherwise required for the installation of a heat exchanger can besaved.

The primary objective of the present invention is to increase the heatdissipation efficiency of a micron-scale wire structure.

Another objective of the present invention is to reduce costs and savespace.

To achieve the above and other objectives, the present inventionprovides another wire structure defined between a first plane and asecond plane parallel to the first plane. The wire structure includes amain body and at least three convex portions. The main body includes acenter and a periphery. The center is defined by the centroidal axis ofthe main body, and the periphery, by the perimeter of the main body. Theconvex portions protrude from and are adjacently arranged around theperiphery. At least one of the convex portions is tangent to the firstplane, and at least two of the convex portions are tangent to the secondplane. The number of the at least one convex portion tangent to thefirst plane is not equal to the number of the at least two convexportions tangent to the second plane. Furthermore, each convex portionis defined by a circular arc, which in turn is defined by a third radius(R2), and the plural convex portions are tangent to an externallytangent circle defined by a first radius (R1) greater than or equal totwice the third radius (R2).

In either of the foregoing wire structures, each convex portion is ormay be defined by a circular arc, bend points may be formed in the crosssection of the wire structure at junctions between the convex portionsand an exposed portion of the periphery, the number of the convexportions may be an odd number, the convex portions may be asymmetricallydistributed about the center, or each two adjacent convex portions mayor may not be in contact with each other.

The present invention further provides a method for designing a wirestructure, and the method is carried as follows. To begin with, N radiallines are set, wherein the radial lines radiate equiangularly outwardfrom the center of the cross section of a wire main body. Then, acircular design line is set, whose center of circle is defined by thecenter of the cross section of the wire main body and whose first radiusis R1. Following that, N identical convex portions are designed, whereinthe cross section of each convex portion is bilaterally symmetric withrespect to a corresponding one of the radial lines, and each convexportion is an outward extension of the wire main body. Additionally, thedistance between the centroid of the cross section of each convexportion and the center of the cross section of the wire main body is thesame, and the cross section of each convex portion has an apex incontact with the circular design line and located on the correspondingradial line. N is an odd number greater than or equal to three.

The present invention also provides a wire structure designed by theforegoing method.

Implementation of the present invention at least achieves the followingadvantageous effects:

1. A wire structure capable of efficient heat dissipation is formed; and

2. As the physical limitations imposed by miniature dimensions on heattransfer are overcome, the cost and space otherwise required forinstalling a heat exchanger can be saved.

Hereinafter, the detailed features and advantages of the presentinvention are described in detail by way of the preferred embodiments ofthe present invention so as to enable persons skilled in the art to gaininsight into the technical disclosure of the present invention,implement the present invention accordingly, and readily understand theobjectives and advantages of the present invention by making referenceto the disclosure of the specification, the claims, and the drawings ofthe present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic drawing of the wire structure according to thefirst embodiment of the present invention;

FIG. 2 is a schematic drawing of the wire structure according to thesecond embodiment of the present invention;

FIG. 3 is a schematic drawing of the wire structure according to thethird embodiment of the present invention;

FIG. 4 is a schematic drawing of the wire structure according to thefourth embodiment of the present invention;

FIG. 5 is a schematic drawing of the wire structure according to thefifth embodiment of the present invention;

FIG. 6 is a schematic drawing of the wire structure according to thesixth embodiment of the present invention;

FIG. 7 is a schematic drawing of the wire structure according to theseventh embodiment of the present invention;

FIG. 8 is a schematic drawing showing a measurement error of the wirestructure of the present invention;

FIG. 9 is the flowchart of the method for designing a wire structureaccording to an embodiment of the present invention;

FIG. 10 schematically shows how N radial lines are set according to anembodiment of the present invention;

FIG. 11 schematically shows how a circular design line is set accordingto an embodiment of the present invention;

FIG. 12 schematically shows how a wire main body is designed accordingto an embodiment of the present invention;

FIG. 13 is a perspective view of the wire structure according to anembodiment of the present invention;

FIG. 14 schematically shows the first aspect of the N identical convexportions designed according to the present invention;

FIG. 15 schematically shows the second aspect of the N identical convexportions designed according to the present invention;

FIG. 16 schematically shows the third aspect of the N identical convexportions designed according to the present invention; and

FIG. 17 schematically shows the fourth aspect of the N identical convexportions designed according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

Please refer to FIG. 1 for a schematic drawing of the wire structureaccording to the first embodiment of the present invention or, moreparticular, a sectional view the wire structure 1. As shown in FIG. 1,the wire structure 1 is defined between a first plane 91 and a secondplane 92 parallel to the first plane 91. The wire structure 1 includes amain body 12 and five convex portions 11. The main body 12 is composedof a center 13 and a periphery 14. The center 13 is defined by thecentroidal axis (i.e., geometric center axis) of the main body 12. Theperiphery 14 is defined by the perimeter of the main body 12 and formsthe boundary of the main body 12. In this embodiment, the cross sectionof the main body 12 is a perfect circle, so the centroid of the crosssection of the main body 12 is the center of circle of the cross sectionof the main body 12. At least three (for example, five) convex portions11 protrude from and are adjacently arranged around the periphery 14.The uppermost convex portion 11 is tangent to the first plane 91 whilethe two lowest convex portions 11 are simultaneously tangent to thesecond plane 92. Hence, the number of the convex portion 11 tangent tothe first plane 91 is not equal to the number of the convex portions 11tangent to the second plane 92. In this embodiment, the total number ofthe convex portions 11 is an odd number, and the convex portions 11 aresymmetrically distributed about the center 13. By “symmetricallydistributed” it is meant that the five convex portions 11 are evenlydistributed along the 360° circumference around the center 13.Therefore, each convex portion 11 spans 72° (360°÷5=72°). In addition,each two adjacent convex portions 11 are in contact with each other.

The cross section of the periphery 14 is a perfect circle defined by abase diameter D1, and the plural convex portions 11 are tangent to anexternally tangent circle 93 defined by a first radius R1, wherein thebase diameter D1 is less than the first radius R1. The cross section ofeach convex portion 11 is defined by a circular arc which in turn isdefined by a third radius R2. The first plane 91 and the second plane 92define a distance H1. The plural convex portions 11 of the wirestructure 1 are tangent to the first plane 91 and the second plane 92such that the wire structure 1 is vertically sandwiched between thefirst plane 91 and the second plane 92. In order to enhance heatdissipation from the small-sized (micron-scale) wire structure 1, theinventor of the present invention conducted numerous experiments andfound the following. The wire structure 1 in this embodiment candissipate heat efficiently when: the first radius R1 of the externallytangent circle 93 is less than 0.134 mm, the third radius R2 of thecircular arc is between 0.045 and 0.0475 mm, the distance H1 between thefirst plane 91 and the second plane 92 is between 0.125 and 2.01 mm, andthe first radius R1 is greater than or equal to twice the third radiusR2 (i.e., R1≧2R2). By satisfying the above conditions, the hair-likewire structure 1 (i.e., with R1<0.134 mm) is significantly enhanced inheat dissipation efficiency and is prevented from melting or burningwhich may otherwise result from an excessively high temperature. Itshould be noted that the externally tangent circle 93 is an imaginarycircle provided only to better explain the structural features of thewire structure 1 and is not a physical element of the wire structure 1.

Second Embodiment

It is understood that the present invention can be implemented in manyother ways as well. Please refer to FIG. 2 for a schematic drawing ofthe wire structure according to the second embodiment of the presentinvention. As shown in FIG. 2, the wire structure 2 has seven (again anodd number) convex portions 21. The two uppermost convex portions 21 aretangent to the first plane 91 while the three lowest convex portions 21are tangent to the second plane 92. Therefore, the number of the convexportions 21 tangent to the first plane 91 is not equal to the number ofthe convex portions 21 tangent to the second plane 92. In thisembodiment, the convex portions 21 are asymmetrically distributed aboutthe center 23. By “asymmetrically distributed” it is meant that theseven convex portions 21 are either different in size or differentlyspaced from the center 23 such that the seven convex portions 21 cannotbe evenly distributed along the 360° circumference around the center 23.As a result, a different included angle is formed between each twoadjacent convex portions 21. Besides, each two adjacent convex portions21 are in contact with each other.

Third Embodiment

FIG. 3 schematically shows the wire structure according to the thirdembodiment of the present invention. As shown in FIG. 3, the wirestructure 3 includes five convex portions. The convex portions 31A and31B are adjacent to and in contact with each other, whereas the convexportions 31B and 31C are adjacent to but not in contact with each other.In consequence, the periphery 35 has an exposed portion between theconvex portions 31B and 31C. The junction between the convex portion 31Band the exposed portion of the periphery 35 is shown in FIG. 3 as a bendpoint 39, and the junction between the convex portion 31C and theexposed portion of the periphery 35, as another bend point 39. Theconvex portions 31B and 31C are spaced by a spacing L1. In thisembodiment, not only do the convex portions increase the surface areafor heat dissipation, but also the exposed portion of the periphery 35serves to dissipate heat. The experiments conducted by the inventor ofthe present invention show that the exposed portion of the periphery 35can dissipate heat efficiently when the spacing L1 is between 0.012 and0.021 mm.

Fourth Embodiment

Please refer to FIG. 4 for a schematic drawing of the wire structureaccording to the fourth embodiment of the present invention. The wirestructure 4 in FIG. 4 has five convex portions 41, each two adjacentones of which are separate from each other. Hence, five spacings L1 aredefined and are preferably equal to facilitate manufacture. However, thefive spacings L1 may also be unequal in applications with particularheat dissipation conditions.

Fifth and Sixth Embodiments

FIGS. 5 and 6 are schematic drawings of the wire structures according tothe fifth and the sixth embodiments of the present inventionrespectively. The periphery 55 of the wire structure 5 in FIG. 5 issmaller in cross section than the periphery 65 of the wire structure 6in FIG. 6. In other words, the base diameter D1 in FIG. 5 is less thanthe base diameter D1 in FIG. 6. Furthermore, the third radius R2 in FIG.5 is less than the third radius R2 in FIG. 6.

Seventh Embodiment

FIG. 7 schematically shows the wire structure according to the seventhembodiment of the present invention. In FIG. 7, the seven convexportions 71 of the wire structure 7 are evenly distributed along theperiphery 74. The uppermost convex portion 71 is tangent to the firstplane 91 while the two lowest convex portions 71 are tangent to thesecond plane 92. Besides, the seven convex portions 71 are identical inboth shape and size.

As demonstrated by the structures in the foregoing embodiments, thepresent invention can substantially enhance thermal diffusion andconvection of a wire structure by increasing its surface area and thusprevent it from experiencing an exceedingly high temperature duringoperation and signal transmission. Here, the issue of heat dissipationfrom a hair-like wire structure (micron-scale, about 0.010 to 0.999 mm)differs substantially from that of a conventional wire(millimeter-scale, about 1 to 2 mm), and this is because heat transferin different scales is accompanied by diverse heat dissipation effects.It is therefore necessary to describe in detail the measurement of thewire structure of the present invention. Please refer to FIG. 8 for aschematic drawing showing a measurement error of the wire structure ofthe present invention. As shown in the drawing, the first plane 91 andthe second plane 92 are spaced by the distance H1. Once the wirestructure 1 is rotated about the center 13, the position of the secondplane 92 is changed accordingly; therefore, the distance H1 is not afixed value. However, with the wire structure 1 as fine as a hair, it isimpossible to visually determine the orientation of the plural convexportions 11 of the wire structure 1. If the diameter D2 of theexternally tangent circle of the wire structure 1 is to be measured bymeasuring the distance H1 between the first plane 91 and the secondplane 92, the variable distance H1 may not give an accurate measurementof the diameter D2. In other words, an error is very likely to existbetween the distance H1 and the diameter D2. Nevertheless, theexperiments conducted by the inventor of the present invention show thatthe error between the distance H1 and the diameter D2 is less than 3% inall the aforesaid embodiments of the present invention. By definition,the diameter D2 of the externally tangent circle is equal to twice theaforesaid first radius R1 of the externally tangent circle.

To sum up, the foregoing limitations in dimensions and configurationhelp increase the heat dissipation efficiency of the micron-scale wirestructure of the present invention. The enhanced heat dissipationcapability, in turn, lends the wire structure great commercial potentialin practical use.

The embodiment shown in FIG. 9 is a method for designing a wirestructure (S100), wherein the method includes the steps of: setting Nradial lines (step S10), setting a circular design line (step S20), anddesigning N identical convex portions (step S30).

The step of setting N radial lines (step S10) is now detailed withreference to FIG. 10. To start with, the center 20 of the cross sectionof a wire main body is set. Then, lines are drawn radially outward fromthe center 20 to form N radial lines 30 which are equally angularlyspaced. In other words, the included angle θ between each two adjacentradial lines 30 is the same. The number N is an odd number greater thanor equal to three and is five in this embodiment. In practice, however,N may also be three, seven, or an odd number not less than nine.

The step of setting a circular design line (step S20) is carried out asfollows. Using the center 20 as the center of circle, the circulardesign line 40 is drawn with a first radius R1, as shown in FIG. 11.

After the circular design line is set (step S20), the wire main body isdesigned as shown in FIGS. 12 and 13. To begin with, a circle fordefining the cross section 50′ of the wire main body is drawn, whereinthe center 20 serves as the center of circle of the cross section 50′,and the second radius is R3. R1 is greater than R3. Then, based on thecross section 50′, a cylindrical main body is designed as the wire mainbody 50.

Next, referring to FIG. 13, N identical convex portions are designed instep S30, wherein each convex portion 60 is an outward extension of thewire main body 50.

More specifically, referring to the sectional view of FIG. 14, eachradial line 30 serves as the center line of the cross section 60′ of oneconvex portion. Therefore, the cross section 60′ of each convex portionis bilaterally symmetric with respect to the corresponding radial line30. In other words, the left half of the cross section 60′ of eachconvex portion is a mirror image of the right half with respect to thecorresponding radial line 30. Moreover, the cross section 60′ of eachconvex portion has an apex 90 in contact with the circular design line40 and located on the corresponding radial line 30.

To put it differently, if the radial lines 30 extend to the circulardesign line 40, the radial lines 30 and the circular design line 40 willintersect at the apexes 90. Besides, when designing the N identicalconvex portions (step S30), the centroid 70 of the cross section 60′ ofeach convex portion is positioned on the corresponding radial line 30such that the shortest distances between each centroid 70 and the center20 are the same. Consequently, the shortest distances between eachcentroid 70 of the cross section 60′ of each convex portion and thecircular design line 40 are also the same.

As shown in FIGS. 15 to 17, each convex portion 60 may be a portion of acylinder. In addition, the distances between the center of circle 80 ofthe cross section of each such cylinder and the center 20 are the same,wherein the distances may be greater than, equal to, or less than R3.When the distances between the center of circle 80 of the cross sectionof each cylinder and the center 20 are greater than R3, the radius ofcurvature of each convex portion 60 is less than the distance betweenthe circular design line 40 and the wire main body 50. When thedistances between the center of circle 80 of the cross section of eachcylinder and the center 20 are equal to R3, the radius of curvature ofeach convex portion 60 is equal to the distance between the circulardesign line 40 and the wire main body 50. When the distances between thecenter of circle 80 of the cross section of each cylinder and the center20 are less than R3, the radius of curvature of each convex portion 60is greater than the distance between the circular design line 40 and thewire main body 50.

The first radius R1 of the circular design line 40 may be less than 2mm. When R1 is less than 0.134 mm and is greater than or equal to twicethe distance between the circular design line 40 and the wire main body50, and the radius of curvature of the cross section 60′ of each convexportion is between 0.045 and 0.0475 mm, the spacing L1 between each twoadjacent convex portions 60 as measured along the boundary of the crosssection 50′ of the wire main body is between 0.012 and 0.021 mm, and thevertical distance between any two parallel tangent lines to the boundaryof the cross section 10′ of the wire structure is between 0.125 and 2.01mm.

Nonetheless, the distance between such parallel tangent lines may varywith product requirements. For example, the distance may be subject tothe sole limitation that it must be less than 2.01 mm, or the distancemay be as short as 0.125 mm when a smaller value is desired, or thedistance may be even smaller in order to meet the requirements ofproduct design. Also, a reduction in the distance may be accompanied bya change in the value of N. For instance, if the distance between suchparallel tangent lines is further reduced, N can be set at three tofacilitate the design and manufacture of the wire. Even though the wirestructure 10 of the present invention may be ten times, a hundred times,or a thousand times thinner than a conventional wire, it can transferand dissipate heat more efficiently.

In the wire structure 10 designed by the method described above, thewire main body 50 is a cylindrical main body, has a circular crosssection 50′ defined by the second radius R3, and is circumferentiallyprovided with the N convex portions 60, wherein N is an odd numbergreater than or equal to three. Further, the centroid 70 of the crosssection 60′ of each convex portion is located on a corresponding one ofthe radial lines 30 radiating outward from the center 20 of the crosssection 50′ of the wire main body and may be shifted along thecorresponding radial line 30, with the cross section 60′ of each convexportion having the same radius of curvature, so as for the boundary ofthe cross section of each convex portion 60 and the circular design line40 defined by the first radius R1 to meet at the corresponding apex 90.

Therefore, as long as the small-sized wire structure 10 has an oddnumber of convex portions 60, the cross section 10′ of the wirestructure can be vertically sandwiched between any two parallel linesand will contact with the two parallel lines at three contact points.Moreover, the vertical distance between the two parallel lines will bethe same, regardless of the orientation in which the cross section 10′of the wire structure is sandwiched between the two parallel lines.

Even if a pair of parallel lines between which the cross section 10′ ofthe wire structure is sandwiched contact with the cross section 10′ atonly two contact points, the error of the vertical distance between thispair of parallel lines will be within 3% of the vertical distancebetween a pair of parallel lines which contact with the cross section10′ sandwiched therebetween at three contact points.

As heat transfer in wire structures 10 of different sizes producesdifferent heat dissipation effects, the shape of the convex portions 60can be designed in accordance with product requirements to adjust thesurface areas of different wire structures 10 for higher heatdissipation efficiency. By doing so, small-sized wire structures 10 areprovided with increased commercial potential in practical use.

The features of the present invention are disclosed above by thepreferred embodiments to allow persons skilled in the art to gaininsight into the contents of the present invention and implement thepresent invention accordingly. The preferred embodiments of the presentinvention should not be interpreted as restrictive of the scope of thepresent invention. Hence, all equivalent modifications or amendmentsmade to the aforesaid embodiments should fall within the scope of theappended claims.

What is claimed is:
 1. A method for designing a wire structure,comprising the steps of: setting N radial lines which radiateequiangularly outward from a center of a cross section of a wire mainbody; setting a circular design line, wherein the circular design linehas a center of circle defined by the center of the cross section of thewire main body and has a first radius; and designing N identical convexportions, each having a cross section bilaterally symmetric with respectto a corresponding one of the radial lines, each said convex portionbeing an outward extension of the wire main body, the center of thecross section of the wire main body being equidistant from a centroid ofthe cross section of each said convex portion, the cross section of eachsaid convex portion having an apex in contact with both the circulardesign line and the corresponding one of the radial line; wherein N isan odd number greater than or equal to three; wherein a verticaldistance between any two parallel tangent lines to a boundary of a crosssection of the wire structure is less than 2.01 mm.
 2. The method ofclaim 1, wherein the wire main body is a cylindrical main body having across section defined by a center of circle and a second radius, thecenter of circle of the cross section of the cylindrical main body beingdefined by the center of the cross section of the wire main body, thefirst radius being greater than the second radius.
 3. The method ofclaim 2, wherein each said convex portion is a portion of a cylinder,and a distance between a center of circle of a cross section of eachsaid cylinder and the center of the cross section of the wire main bodyis the same and the distance between the center of circle of the crosssection of each said cylinder and the center of the cross section of thewire main body is greater than the second radius.
 4. The method of claim2, wherein each said convex portion is a portion of a cylinder, and adistance between a center of circle of a cross section of each saidcylinder and the center of the cross section of the wire main body isthe same and the distance between the center of circle of the crosssection of each said cylinder and the center of the cross section of thewire main body is equal to the second radius.
 5. The method of claim 2,wherein each said convex portion is a portion of a cylinder, and adistance between a center of circle of a cross section of each saidcylinder and the center of the cross section of the wire main body isthe same and the distance between the center of circle of the crosssection of each said cylinder and the center of the cross section of thewire main body is less than the second radius.
 6. The method of claim 1,wherein each said convex portion is defined by a circular arc, thecircular arc being defined by a third radius, and the at least threeconvex portions are tangent to an externally tangent circle defined bythe first radius greater than or equal to twice the third radius.
 7. Themethod of claim 6, wherein the first radius is less than 0.134 mm. 8.The method of claim 6, wherein the third radius of the circular arc isbetween 0.045 and 0.0475 mm.
 9. A wire structure designed by a method ofdesigning a wire structure, the steps of the method comprising: settingN radial lines which radiate equiangularly outward from a center of across section of a wire main body; setting a circular design line,wherein the circular design line has a center of circle defined by thecenter of the cross section of the wire main body and has a firstradius; and designing N identical convex portions, each having a crosssection bilaterally symmetric with respect to a corresponding one of theradial lines, each said convex portion being an outward extension of thewire main body, the center of the cross section of the wire main bodybeing equidistant from a centroid of the cross section of each saidconvex portion, the cross section of each said convex portion having anapex in contact with both the circular design line and the correspondingone of the radial line; wherein N is an odd number greater than or equalto three; wherein a vertical distance between any two parallel tangentlines to a boundary of a cross section of the wire structure is lessthan 2.01 mm.
 10. The wire structure of claim 9, wherein each saidconvex portion is defined by a circular arc, the circular arc beingdefined by a third radius, and the at least three convex portions aretangent to an externally tangent circle defined by the first radiusgreater than or equal to twice the third radius.
 11. A wire structuredefined between a first plane and a second plane parallel to the firstplane, the wire structure comprising: a main body comprising a centerand a periphery, wherein the center is defined by a centroidal axis ofthe main body, and the periphery is defined by a perimeter of the mainbody; and at least three convex portions which protrude from and areadjacently arranged around the periphery; wherein a distance between thefirst plane and the second plane is less than 2.01 mm.
 12. The wirestructure of claim 11, wherein the number of the at least three convexportions is an odd number.
 13. The wire structure of claim 11, whereinthe at least three convex portions are asymmetrically distributed aboutthe center.
 14. The wire structure of claim 11, wherein a junctionbetween a said convex portion and an exposed portion of the peripheryforms a bend point in a cross section of the wire structure.
 15. Thewire structure of claim 11, wherein at least one said convex portionbeing tangent to the first plane, at least two said convex portionsbeing tangent to the second plane.
 16. The wire structure of claim 15,wherein the number of the at least one convex portion tangent to thefirst plane is not equal to the number of the at least two convexportions tangent to the second plane.
 17. The wire structure of claim11, wherein each said convex portion is defined by a circular arc, thecircular arc being defined by a third radius, and the at least threeconvex portions are tangent to an externally tangent circle defined by afirst radius (R1) greater than or equal to twice the third radius. 18.The wire structure of claim 17, wherein the first radius is less than0.134 mm.
 19. The wire structure of claim 17, wherein the third radiusof the circular arc is between 0.045 and 0.0475 mm.
 20. The wirestructure of claim 11, wherein the two adjacent convex portions arespaced by a spacing, the spacing substantially is between 0.012 and0.021 mm.